Make the generated nmake.ads unit look more like it was written with
GNAT style rules in mind; semantics is unaffected.

Cleanup related to fix of default initialization in multi-dimensional
arrays, which used to explicitly call the Nmake.Make_Null routine.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

	* gen_il-gen.adb (Put_Make_Decls): Put pragma Inline in a
	dedicated line, so that the current indentation is taken into
	account.